Light emitting device and method of manufacturing the same

ABSTRACT

To provide a light emitting device high in reliability with a pixel portion having high definition with a large screen. According to a light emitting device of the present invention, on an insulator ( 24 ) provided between pixel electrodes, an auxiliary electrode ( 21 ) made of a metal film is formed, whereby a conductive layer ( 20 ) made of a transparent conductive film in contact with the auxiliary electrode can be made low in resistance and thin. Also, the auxiliary electrode ( 21 ) is used to achieve connection with an electrode on a lower layer, whereby the electrode can be led out with the transparent conductive film formed on an EL layer. Further, a protective film ( 32 ) made of a film containing hydrogen and a silicon nitride film which are laminated is formed, whereby high reliability can be achieved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device and,particularly, to a light emitting device having an organic lightemitting element formed over a substrate having an insulating surfaceand a manufacturing method therefor. The present invention also relatesto a module in which an IC etc. including a controller is mounted on apanel having the organic light emitting element. Note that, in thisspecification, the panel and the module which have the organic lightemitting element are collectively referred to as a light emittingdevice. Further, the present invention relates to an apparatus formanufacturing the light emitting device.

Note that, in this specification, the term semiconductor device refersto the devices in general which can function by utilizing semiconductorcharacteristics. The light emitting device, an electro-optic device, asemiconductor circuit, and an electronic device are all included in thecategory of the semiconductor device.

2. Description of the Related Art

Techniques of forming TFTs (thin film transistors) on substrates havebeen progressing greatly in recent years, and developments in theirapplication to active matrix display devices is advancing. Inparticular, TFTs that use polysilicon films have a higher electric fieldeffect mobility (also referred to as mobility) than TFTs that useconventional amorphous silicon films, and therefore high speed operationis possible. Developments in performing control of pixels by formingdriver circuits made from TFTs that use polysilicon films over asubstrate on which the pixels are formed have therefore beenflourishing. It has been expected that various advantages can beobtained by using active matrix display devices in which pixels anddriver circuits are mounted on the same substrate, such as reductions inmanufacturing cost, miniaturization of the display device, increases inyield, and increases in throughput.

Furthermore, research on active matrix light emitting devices usingorganic light emitting elements as self light emitting elements(hereinafter referred to simply as light emitting devices) has becomemore active. The light emitting devices are also referred to as organicEL displays (OELDs) and organic light emitting diodes (OLEDs).

TFT switching elements (hereinafter referred to as switching elements)are formed for each pixel in active matrix light emitting devices, anddriver elements for performing electric current control using theswitching TFTs (hereinafter referred to as electric current controlTFTs) are operated, thus making EL layers (strictly speaking, lightemitting layers) emit light. For example, a light emitting devicedisclosed in JP 10-189252 is known.

Organic light emitting elements are self light emitting, and thereforehave high visibility. Backlights, necessary for liquid crystal displaydevices (LCDs), are not required for organic light emitting elements,which are optimal for making display devices thinner and have nolimitations in viewing angle. Light emitting devices using organic lightemitting elements are consequently being focused upon as substitutes forCRTs and LCDs.

Note that EL elements have a layer containing an organic compound inwhich luminescence develops by the addition of an electric field(Electro Luminescence) (hereinafter referred to as EL layer), an anode,and a cathode. There is light emission when returning to a base statefrom a singlet excitation state (fluorescence), and light emission whenreturning to a base state from a triplet excitation state(phosphorescence) in the organic compound layer, and it is possible toapply both types of light emission to light emitting devicesmanufactured by the manufacturing apparatus and film formation method ofthe present invention.

EL elements have a structure in which an EL layer is sandwiched betweena pair of electrodes, and the EL layer normally has a laminatestructure. A “hole transporting layer/light emitting layer/electrontransporting layer” laminate structure can be given as a typicalexample. This structure has extremely high light emitting efficiency,and at present almost all light emitting devices undergoing research anddevelopment employ this structure.

Further, a structure in which: a hole injecting layer, a holetransporting layer, a light emitting layer, and an electron transportinglayer are laminated in order on an anode; or a hole injecting layer, ahole transporting layer, a light emitting layer, an electrontransporting layer, and an electron injecting layer are laminated inorder on an anode may also be used. Fluorescent pigments and the likemay also be doped into the light emitting layers. Further, all of thelayers may be formed by using low molecular weight materials, and all ofthe layers may be formed by using high molecular weight materials.

The conventional active matrix type light emitting device is composed ofa light emitting element in which an electrode electrically connectedwith TFT on the substrate is formed as an anode, then the organiccompound layer was formed on the anode. Light generated at the organiccompound layer is radiated from the anode that is a transparentelectrode to TFT.

However, in this structure, the problem has arisen when the resolutionis intended to be risen that an aperture ratio is limited due to anarrangement of TFT and wirings in the pixel unit.

SUMMARY OF THE INVENTION

According to the present invention, manufactured is an active matrixlight emitting device having the light emitting element with a structurein which an electrode on the TFT side electrically connected to the TFTon the substrate is formed as a cathode, on which an organic compoundlayer and an anode as a transparent electrode are formed in the statedorder (hereinafter, referred to as upper surface emission structure).Alternatively, manufactured is an active matrix light emitting devicehaving the light emitting element with a structure in which an electrodeon the TFT side electrically connected to the TFT on the substrate isformed as an anode, on which an organic compound layer and a cathode asa transparent electrode are formed in the stated order (hereinafter,also referred to as upper surface emission structure).

In the above-mentioned respective structures, there arises a problemconcerning a higher film resistance of a transparent electrode. Inparticular, when a film thickness of the transparent electrode isreduced, the film resistance further increases. If the film resistanceof the transparent electrode serving as an anode or a cathode isincreased, there arises a problem in that a potential distribution inthe surface becomes nonuniform due to voltage drop, which involvesvariations in luminance of the light emitting element. Accordingly, anobject of the present invention is to provide a light emitting devicehaving a structure useful in decreasing the film resistance of thetransparent electrode of the light emitting element and a manufacturingmethod therefor and further to provide an electronic device using theabove light emitting device as a display portion.

In addition, another object of the present invention is to increasereliability in the light emitting element and the light emitting device.

According to the present invention, in manufacturing the light emittingelement formed over the substrate, a conductive film is formed on aninsulator arranged between pixel electrodes prior to formation of anorganic compound layer for the purpose of suppressing the filmresistance of the transparent electrode.

Further, the present invention is characterized in that a lead wiring isformed using the above conductive film to achieve connection with otherwirings on a lower layer as well.

According to a structure of the invention disclosed in thisspecification, there is provided a light emitting device, including:

-   -   a pixel portion having a plurality of light emitting elements        each including: a first electrode; an organic compound layer        formed on the first electrode in contact therewith; and a second        electrode formed on the organic compound layer in contact        therewith;    -   a driver circuit; and    -   a terminal portion,    -   the device being characterized in that:    -   in the pixel portion, end portions of the first electrode        connected to a thin film transistor are covered with an        insulator, a third electrode made of a conductive material is        formed on the insulator, the organic compound layer is formed on        the insulator and the first electrode, and the second electrode        is formed on the organic compound layer and the third electrode        in contact therewith; and    -   a portion where a wiring made of a material identical to that of        the third electrode or that of the second electrode is connected        with a wiring extended from a terminal is formed between the        terminal portion and the pixel portion.

In the above-mentioned structure, the third electrode may have a patternshape identical to that of the insulator. In this case, it is formedusing a mask identical to that of the insulator.

Alternatively, in the above-mentioned structure, the third electrode mayhave a pattern shape different from that of the insulator. In this case,after patterning the insulator, a film made of a conductive material isformed to form the third electrode using a mask different from that usedfor patterning the insulator.

Also, according to another structure of the present invention, inmanufacturing a light emitting element formed over a substrate, aconductive film is formed on an insulator arranged between pixelelectrodes prior to formation of the organic compound layer, and afterthe organic compound layer and a transparent electrode are formed, anelectrode made of a material high in conductivity is formed on thetransparent electrode to realize low film resistance of the transparentelectrode. Note that, the electrode formed on the transparent electrodeis not formed in a portion serving as a light emitting region. Further,the present invention is also characterized in that a lead wiring isformed using the conductive film to achieve connection with otherwirings formed on a lower layer.

According to another structure of the invention disclosed in thisspecification, there is provided the light emitting device, including:

-   -   a pixel portion having a plurality of light emitting elements        each including: a first electrode; an organic compound layer        formed on the first electrode in contact therewith; and a second        electrode formed on the organic compound layer in contact        therewith;    -   a driver circuit; and    -   a terminal portion,    -   the device being characterized in that:    -   in the pixel portion, end portions of the first electrode        connected to a thin film transistor are covered with an        insulator, the organic compound layer is formed on a part of the        insulator and the first electrode, the second electrode is        formed on the organic compound layer in contact therewith, and a        third electrode made of a conductive material is formed on a        region of the second electrode which is not overlapped with the        first electrode in contact therewith; and    -   a portion where a wiring made of a material identical to that of        the third electrode or that of the second electrode is connected        with a wiring extended from a terminal is formed between the        terminal portion and the pixel portion.

Also, in the above-mentioned structures, the light emitting device ischaracterized in that the second electrode is a cathode or an anode ofthe light emitting element.

Also, in the above-mentioned structures, the light emitting device ischaracterized in that the third electrode is made of a material havingelectric resistance lower than that constituting the second electrodeand is made of poly-Si doped with an impurity element imparting aconductivity type, an element selected from the group consisting of W,WSi_(x), Al, Ti, Mo, Cu, Ta, Cr, and Mo, a film mainly containing analloy material or a compound material mainly containing the element, ora laminate film thereof. For example, it is preferable that the thirdelectrode is an electrode made of a laminate having a nitride layer or afluoride layer as an uppermost layer.

Also, in the above-mentioned structures, the light emitting device ischaracterized in that the first electrode is a cathode or an anode ofthe light emitting element. For example, when the second electrode is acathode, the first electrode serves as an anode, whereas when the secondelectrode is an anode, the first electrode serves as a cathode.

Also, in the above-mentioned structures, the light emitting device ischaracterized in that the insulator is a barrier (also referred to asbank) made of organic resin covered with an inorganic insulating film oris an inorganic insulating film. Note that, the light emitting device ischaracterized in that the inorganic insulating film is an insulatingfilm mainly containing silicon nitride with a film thickness of 10 to100 nm.

Also in the light emitting device, there is a problem in that in a pixelemitting no light, an incident outside light (light outside the lightemitting device) is reflected by the rear surface of the cathode(surface brought into contact with an light emitting layer) which actsas mirror and outside scenes are reflected in an observation surface(surface facing an observer side). In order to avoid the problem, thefollowing is devised such that a circular polarization film is attachedto the observation surface of the light emitting device to prevent theobservation surface from reflecting the outside scenes. However, therearises a problem in that the circular polarization film is extremelyexpensive, which involves an increase in manufacturing cost.

Another object of the present invention is to prevent the light emittingdevice from acting as mirror without using the circular polarizationfilm to accordingly provide an inexpensive light emitting device whichattains low manufacturing cost thereof. Accordingly, the presentinvention is characterized by using an inexpensive color filter insteadof using the circular polarization film. In the above-mentionedstructure, it is preferable to provide a color filter corresponding toeach pixel in the light emitting device in order to increase colorpurity. Also, a black portion (black organic resin) of the color filtermay be arranged so as to overlap each portion between light emittingregions. Further, the black portion (black colored layer) of the colorfilter may be also arranged so as to overlap a portion where differentorganic compound layers are partially overlapped with each other.

Note that, the color filter is provided in an emission direction of anemitted light, i.e., provided between the light emitting element and theobserver. For example, when the light is not allowed to pass through thesubstrate having formed the light emitting element thereon, the colorfilter may be attached to the sealing substrate. Alternatively, when thelight is allowed to pass through the substrate having formed the lightemitting element thereon, the color filter may be attached thereto.Thus, it is possible to dispense with the circular polarization film.

In addition, it is extremely effective that as an anode on a layercontaining an organic compound, a transparent conductive film(typically, ITO or ZnO) is used, on which a protective film made of aninorganic insulating film is formed. The following is also effective: asa cathode containing an organic compound, a metal thin film (with a filmthickness allowing a light to pass the film) made of Al, Ag, and Mg, oran alloy thereof (typically, AlLi) is used, on which the protective filmmade of the inorganic insulating film is formed.

Also, before the protective film made of the inorganic insulating filmis formed, it is preferable that a film containing hydrogen, typically athin film mainly containing carbon, or a silicon nitride film is formedby a plasma CVD method or a sputtering method. Also, the film containinghydrogen may be a laminate film consisting of the thin film mainlycontaining carbon and the silicon nitride film.

Further, according to another structure of the present invention, thereis provided the light emitting device including a light emitting elementover a substrate having an insulating surface, the light emittingelement including an anode, a cathode, and an organic compound layerinterposed between the anode and the cathode, characterized in that thelight emitting element is covered with a film containing hydrogen.

If heat treatment is performed within a range of temperature to whichthe organic compound layer can be resistant and heat generated when thelight emitting element emits the light is utilized, hydrogen can bediffused from the film containing hydrogen to terminate defects in theorganic compound layer with hydrogen (termination). By terminating thedefects in the organic compound layer with hydrogen, the light emittingdevice can be increased in its reliability. Also, when the filmcontaining hydrogen is formed, hydrogen turned into a plasma can be usedto terminate defects in the organic compound layer with hydrogen. Theprotective film formed so as to cover the film containing hydrogen alsofunctions to block hydrogen diffused toward the protective film side andto efficiently diffuse hydrogen into the organic compound layer toterminate defects in the organic compound layer with hydrogen. Further,the film containing hydrogen can serve as the protective film for thelight emitting element.

Further, the film containing hydrogen can serve as a buffer layer. Whenthe silicon nitride film is formed in contact with the transparentconductive film by a sputtering method, there is a possibility thatimpurities (In, Sn, Zn, etc.) contained in the transparent conductivefilm are mixed into the silicon nitride film. However, by forming thefilm containing hydrogen as a buffer layer therebetween, it is alsopossible to prevent mixture of the impurities into the silicon nitridefilm. According to the above structure, the buffer layer is formed, sothat the impurities (In, Sn, etc.) can be prevented from mixing thereinfrom the transparent conductive film and a superior protective filmhaving no impurities can be formed.

According to another structure of the present invention, there isprovided the light emitting device including a light emitting elementover a substrate having an insulating surface, the light emittingelement including an anode, a cathode, and an organic compound layerinterposed between the anode and the cathode, characterized in that thelight emitting element is covered with a film containing hydrogen whichis covered with a protective film made of an inorganic insulating film.

Also, a manufacturing method capable of realizing the above-mentionedstructure is included in the present invention. According to a structurerelating to a manufacturing method of the present invention, there isprovided a manufacturing method for a light emitting device,characterized by including:

-   -   forming a TFT on an insulating surface;    -   forming a cathode electrically connected to the TFT;    -   forming an organic compound layer on the cathode; and    -   forming an anode on the organic compound layer and then forming        a film containing hydrogen on the anode.

Also, according to another structure relating to the manufacturingmethod of the present invention, there is provided the manufacturingmethod for a light emitting device, characterized by including:

-   -   forming a TFT on an insulating surface;    -   forming an anode electrically connected to the TFT;    -   forming an organic compound layer on the anode; and    -   forming a cathode on the organic compound layer and then forming        a film containing hydrogen on the cathode.

In the above-mentioned structures relating to the manufacturing methodof the present invention, the method is characterized in that the filmcontaining hydrogen is formed by a plasma CVD method or a sputteringmethod within a range of temperature to which the organic compound layercan be resistant, for example, a range from room temperature to 100° C.or less and that the film containing hydrogen is a thin film mainlycontaining carbon or a silicon nitride film.

In the above-mentioned structures relating to the manufacturing methodof the present invention, the method is characterized in that a step offorming the organic compound layer is performed by an evaporationmethod, a coating method, an ion plating method, or an ink jet method.

In the above-mentioned structures relating to the manufacturing methodof the present invention, the method is characterized in that aprotective film made of an inorganic insulating film is formed on thefilm containing hydrogen.

In the above-mentioned structures relating to the manufacturing methodof the present invention, the method is characterized in that when thefilm containing hydrogen is formed, a defect in the organic compoundlayer is terminated with hydrogen.

Also, in order to prevent deterioration due to moisture or oxygen, whenthe light emitting element is sealed with a sealing can or a sealingsubstrate, a space to be sealed may be filled with a hydrogen gas orwith hydrogen and inert gas (rare gas or nitrogen).

According to another structure of the present invention, there isprovided the light emitting device including a light emitting elementover a substrate having an insulating surface, the light emittingelement including an anode, a cathode, and an organic compound layerinterposed between the anode and the cathode, characterized in that thelight emitting element is sealed with a substrate having alight-transmissive property and a sealing member, and a sealed spacecontains hydrogen.

In the above-mentioned structure, the light emitting device ischaracterized in that the light emitting element is covered with thefilm containing hydrogen (thin film mainly containing carbon or siliconnitride film).

Also, with the above-mentioned structure, heat treatment is performedwithin a range of temperature to which the organic compound layer can beresistant and heat generated when the light emitting element emits thelight is utilized, so that hydrogen can be diffused from the spacecontaining hydrogen to terminate defects in the organic compound layerwith hydrogen. By terminating defects in the organic compound layer withhydrogen, the light emitting device can be increased in its reliability.

Note that, in this specification, all the layers provided between thecathode and the anode are collectively referred to as an EL layer. Thus,the above-mentioned hole injection layer, hole transportation layer,light emitting layer, electron transportation layer, and electroninjection layer are all included in the EL layer.

The present invention is characterized in that the thin film mainlycontaining carbon is a DLC (diamond like carbon) film having a thicknessof 3 to 50 nm. The DLC film has an SP³ bond as a bond between carbons interms of short range order but has an amorphous structure in a macrolevel. The composition of the DLC film is carbon and hydrogen with thecontents of 70 to 95 atoms % and 5 to 30 atoms, respectively. Thus, thefilm is extremely hard and superior in an insulating property. Such aDLC film is characterized in that gas permeability with respect tomoisture, oxygen, etc. is low. Also, it is known that the film hashardness of 15 to 25 GPa as a result of measurement by a microhardnessmeter.

The DLC film can be formed by a plasma CVD method (typically, RF plasmaCVD method, microwave CVD method, electron cyclotron resonance (ECR) CVDmethod, or the like), a sputtering method, or the like. Any filmformation method can be adopted to form the DLC film with goodadhesiveness. The DLC film is formed with the substrate placed on thecathode. Also, when a negative bias is applied thereto and ion impact isutilized to some degree, a minute and hard film can be formed.

As a reaction gas used for film formation, a hydrogen gas and ahydrocarbon-based gas (e.g., CH₄, C₂H₂, C₆H₆, or the like) are used,which are ionized due to glow discharge, and ions are accelerated andabutted against a cathode to which a negative self-bias is applied tothereby form the film. Thus, a minute and smooth DLC film can beobtained.

Also, the DLC film is characterized by including a transparent orsemi-transparent insulating film with respect to a visible light.

Further, in this specification, the term transparent with respect to thevisible light means a state in which transmittance of the visible lightis 80 to 100% and the term semi-transparent with respect to the visiblelight means a state in which transmittance of the visible light is 50 to80%.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A to 1C are sectional views in accordance with Embodiment Mode 1of the present invention;

FIG. 2 is a top view in accordance with Embodiment Mode 1 of the presentinvention;

FIGS. 3A to 3D each show a terminal portion in accordance withEmbodiment Mode 1 of the present invention;

FIGS. 4A and 4B each show a laminate structure in accordance withEmbodiment Mode 2 of the present invention;

FIGS. 5A and 5B are top views in accordance with Embodiment Mode 3 ofthe present invention;

FIGS. 6A to 6C are sectional views in accordance with Embodiment Mode 3of the present invention;

FIGS. 7A to 7C are top views in accordance with Embodiment Mode 3 of thepresent invention;

FIGS. 8A to 8C each show a mask in accordance with Embodiment Mode 3 ofthe present invention:

FIGS. 9A to 9C are sectional views in accordance with Embodiment Mode 4of the present invention;

FIGS. 10A to 10C are sectional views in accordance with Embodiment Mode5 of the present invention;

FIG. 11 shows an example of a manufacturing apparatus in accordance withEmbodiment 2 of the present invention;

FIG. 12 shows an example of a manufacturing apparatus in accordance withEmbodiment 2 of the present invention;

FIGS. 13A to 13F each show an example of an electronic device; and

FIGS. 14A to 14C each show an example of an electronic device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment modes of the present invention will be described below.

Embodiment Mode 1

FIG. 2 is a top view of an EL module. In the figure, over a substrate(also referred to as TFT substrate) where a number of TFTs are provided,there are formed a pixel portion 40 used for display, driver circuits 41a and 41 b for driving pixels of the pixel portion, a connecting portionfor connecting an electrode formed on an EL layer and a lead wiring, anda terminal portion 42 to which an FPC is attached for connecting anexternal circuit therewith. Also, a substrate for sealing an EL elementand a sealing member 33 are used to attain a sealed state. FIG. 1A is asectional view taken along the dashed line A-A′ of FIG. 2.

The pixels are arranged regularly in the direction of the dashed lineA-A′. Here, an example of the pixels arranged in the order of R, G, andB in an X direction will be shown.

In FIG. 1A, a light emitting region (R) indicates a region for emittinga red light; a light emitting region (G), a region for emitting a greenlight; and a light emitting region (B), a region for emitting a bluelight. These light emitting regions of three colors realize a lightemitting display device capable of full color display.

Also, in FIG. 1A, a TFT 1 is an element for controlling a currentflowing in an EL layer 17 emitting a red light and reference numerals 4and 7 denote source or drain electrodes. Further, a TFT 2 is an elementfor controlling a current flowing in an EL layer 18 emitting a greenlight and reference numerals 5 and 8 denote source or drain electrodes.A TFT 3 is an element for controlling a current flowing in an EL layer19 emitting a blue light and reference numerals 6 and 9 denote source ordrain electrodes. Reference numerals 15 and 16 denote interlayerinsulating films formed of an organic insulating material or aninorganic insulating film material.

Reference numerals 11 to 13 each denote an anode (or a cathode) of theorganic light emitting element and 20 denotes a cathode (or an anode) ofthe organic light emitting element. In this example, the cathode 20 ismade of a laminate film consisting of a thin metal layer (typically, analloy of MgAg, MgIn, AlLi, or the like) and a transparent conductivefilm (an alloy of an indium oxide and a tin oxide (ITO), an alloy of anindium oxide and a zinc oxide (In₂O₃—ZnO), a zinc oxide (ZnO), and thelike), through which light from the respective light emitting elementspasses. Note that, the transparent conductive film is provided not tofunction as a cathode but to decrease the electric resistance. As ananode, the following may be used: a material having a high workfunction, specifically, platinum (Pt), chromium (Cr), tungsten (W), or anickel (Ni); a transparent conductive film (ITO, ZnO, or the like); anda laminate thereof.

Also, organic insulators 24 (also referred to as barrier or bank) coverboth ends of the anodes (or cathodes) 11 to 13 and portionstherebetween. Further, the organic insulators 24 are covered withinorganic insulating films 14. An organic compound layer is partiallyformed on each organic insulator 24.

On the organic insulators 24 (also referred to as barrier or bank)covered with the inorganic insulating films 14, auxiliary electrodes 21are formed. The auxiliary electrodes 21 function to decrease an electricresistance value of the cathode (or the anode). The above-mentionedtransparent conductive film has a relatively high resistance value, sothat it is difficult to achieve a large screen. However, by providingthe auxiliary electrodes 21, the electrodes serving as a cathode (or ananode) can be reduced in resistance as a whole. In addition, thethickness of the transparent conductive film can be reduced.

Further, connection with the wiring or the electrode on the lower layeris achieved using the auxiliary electrodes 21. The auxiliary electrodes21 may be subjected to film formation or patterning before the EL layeris formed. Through a sputtering method, an evaporation method, or thelike, the auxiliary electrodes 21 may be formed of poly-Si doped with animpurity element imparting a conductivity type, an element selected fromthe group consisting of W, WSi_(x), Al, Ti, Mo, Cu, Ta, Cr, and Mo, afilm mainly containing an alloy material or a compound material mainlycontaining the element, or a laminate film thereof. Thus, if thetransparent conductive film is formed on the auxiliary electrodes 21 incontact therewith which are brought into contact with the electrode onthe lower layer, the cathode can be led out. Note that, FIG. 1C is asectional view taken along the dashed line C-C′ of FIG. 2. In FIG. 1C,electrodes connected by the dotted line are electrically connected toeach other. Also, in the terminal portion, an electrode of the terminalis formed of the same material as a cathode 10.

Also, a sealing substrate 30 is bonded thereto using the sealing member33 so as to maintain an interval of about 10 μm, so that all the lightemitting elements are sealed. Here, it is desirable to turn the sealingmember 33 into a shape like a frame with a small width so as topartially overlap the driver circuit. Annealing is preferably performedin the vacuum for degassing immediately before the sealing substrate 30is bonded thereto using the sealing member 33. Also, it is preferable tobond the sealing substrate 30 thereto in an atmosphere containinghydrogen and an inert gas (rare gas or nitrogen) and to allow the spacesealed by a protective film 32, the sealing member 33, and the sealingsubstrate 30 to contain hydrogen. Heat generated when the light emittingelement emits a light is utilized, which makes it possible to diffusehydrogen from the space containing it to thereby terminate defects inthe organic compound layer with hydrogen. By terminating the defects inthe organic compound layer with hydrogen, the light emitting device canbe increased in its reliability.

Further, in order to increase color purity, color filters correspondingto the respective pixels are provided on the sealing substrate 30. Amongthe color filters, a red colored layer 31 b is provided opposite to thered light emitting region (R), a green colored layer 31 c is providedopposite to the green light emitting region (G), and a blue coloredlayer 31 d is provided opposite to the blue light emitting region (B).Further, regions other than the light emitting regions arelight-shielded with black portions of the color filters, i.e.,light-shielding portions 31 a. Here, the light-shielding portions 31 aare formed of a metal film (containing chromium etc.) or an organic filmcontaining a black pigment.

In the present invention, provision of the color filters makes acircular polarization plate unnecessary.

Also, FIG. 1B is a sectional view taken along the dashed line B-B′ ofFIG. 2. Also in FIG. 1B, the inorganic insulating films 14 cover bothends of portions denoted by 11 a to 11 c and regions therebetween. Inthis case, although an example in which an EL layer 17 emitting a redlight is used in common is shown, the present invention is notparticularly limited to the above. It may be also possible to form theEL layer for each pixel emitting the same color.

Also, in FIGS. 1A to 1C, the protective film 32 is formed so as toincrease reliability of the light emitting device, which is aninsulating film mainly containing silicon nitride or silicon oxynitrideand formed by the sputtering method. Also, in FIGS. 1A to 1C, theprotective film is preferably made as thin as possible such that anemitted light passes therethrough.

Further, the protective film 32 is formed after a film containinghydrogen is formed in order to increase reliability of the lightemitting device. By forming the film containing hydrogen prior to theformation of the protective film 32, the defects in the organic compoundlayers 17 to 19 are terminated. The film containing hydrogen may be athin film mainly containing carbon or a silicon nitride film. As for amethod of forming the film containing hydrogen, the film is formed by aplasma CVD method or a sputtering method within a range of temperatureto which the organic compound layer can be resistant, for example, arange from room temperature to 100° C. or less. Note that, in FIGS. 1Ato 1C, the film containing hydrogen is assumed to partially constitutethe protective film and thus is omitted in the figure. Also, the filmcontaining hydrogen may be used as a buffer layer for relaxing a filmstress of the protective film 32.

Needless to say, the present invention is not limited to the structureof FIG. 1C. An example of a structure partially different from the oneof FIG. 1C is shown in FIGS. 3A to 3D. Here, in FIGS. 3A to 3D,components identical to those of FIGS. 1A to 1C are denoted by identicalsymbols for simplicity.

FIG. 1C shows an example in which the electrode formed of the samematerial as the cathode (transparent electrode) is provided in theterminal portion. However, FIG. 3A shows an example in which anelectrode formed of the same material as a gate electrode of the TFT (aW film as an upper layer and a TaN film as a lower layer) is used toachieve connection with an FPC.

Also, FIG. 3B shows an example in which an electrode 10 made of the samematerial as a pixel electrode (anode) is used to achieve connection withthe FPC. In this example, the electrode 10 is formed on the electrodemade of the same material as the gate electrode of the TFT (a W film asan upper layer and a TaN film as a lower layer) in contact therewith.

FIG. 3C shows an example in which an electrode for achieving connectionwith the FPC is an electrode formed of the same material as the cathode20 (transparent electrode) formed on the electrode 10 made of the samematerial as the pixel electrode (anode) formed on the lead wiring(wiring in which a TiN film, an Al film, and a TiN film are laminated inthe stated order) of the TFT.

FIG. 3D shows an example in which an electrode for achieving connectionwith the FPC is an electrode made of the same material as the cathode 20(transparent electrode) formed on the lead wiring (wiring in which a TiNfilm, an Al film, and a TiN film are laminated in the stated order) ofthe TFT.

Embodiment Mode 2

Here, the film containing hydrogen and the protective film will bedescribed with reference to FIGS. 4A and 4B.

FIG. 4A is a schematic diagram showing an example of a laminatestructure of the EL element. In FIG. 4A, reference numeral 200 denotes acathode (or an anode); 201, an EL layer; 202, an anode (or a cathode);203, a DLC film containing hydrogen; and 204, a protective film. Whenthe emitted light is caused to pass through the anode 202, a conductivefilm having a light-transmissive property (ITO, ZnO, etc.) is preferablyused as the anode 202. Also, as the cathode 200, a metal film (an alloyfilm of MgAg, MgIn, AlLi, etc. or a film formed by coevaporation ofaluminum and an element belonging to Group 1 or 2 in the periodic table)or a laminate thereof is preferably used.

The protective film 204 may be made of an insulating film mainlycontaining silicon nitride or silicon oxynitride which is obtained by asputtering method (DC system or RF system). The silicon nitride film maybe obtained by using a silicon target through the formation in anatmosphere containing nitrogen and argon. Also, a silicon nitride targetcan be used. The protective film 204 may be also formed by a filmformation apparatus using a remote plasma. Further, when the emittedlight is caused to pass through the protective film, it is preferablethat the protective film is made as thin as possible.

The DLC film 203 containing hydrogen contains carbon and hydrogen withthe contents of 70 to 95 atoms % and 5 to 30 atoms %, respectively andthus is extremely hard and superior in an insulating property. The DLCfilm containing hydrogen may be formed by a plasma CVD method(typically, RF plasma CVD method, microwave CVD method, electroncyclotron resonance (ECR) CVD method, or the like), a sputtering method,or the like.

As a method of forming the DLC film 203 containing hydrogen, the film isformed within a range of temperature to which the organic compound layercan be resistant, for example, a range, from room temperature to 100° C.or less.

As a reaction gas used for the film formation when the plasma isgenerated, a hydrogen gas and a hydrocarbon-based gas (e.g., CH₄, C₂H₂,C₆H₆, or the like) may be used.

Heat treatment is performed within a range of temperature to which theorganic compound layer can be resistant and heat generated when thelight emitting element emits the light is utilized, so that hydrogen canbe diffused from the DLC film containing hydrogen to terminate defectsin the organic compound layer with hydrogen (termination). Byterminating the defects in the organic compound layer with hydrogen, thelight emitting device can be increased in its reliability. Also, whenthe DLC film containing hydrogen is formed, hydrogen turned into aplasma can be used to terminate defects in the organic compound layerwith hydrogen. In addition, the protective film formed so as to coverthe DLC film containing hydrogen functions to block hydrogen diffusedtoward the protective film side and to efficiently diffuse hydrogen intothe organic compound layer to thereby terminate defects in the organiccompound layer with hydrogen as well. Note that, the DLC film containinghydrogen can serve as the protective film for the light emittingelement.

Further, the DLC film containing hydrogen can also serve as a bufferlayer. When the silicon nitride film is formed in contact with the filmmade of the transparent conductive film by a sputtering method, there isa possibility that impurities (In, Sn, Zn, etc.) contained in thetransparent conductive film are mixed into the silicon nitride film.However, by forming the DLC film containing hydrogen as a buffer layertherebetween, it is also possible to prevent mixture of the impuritiesinto the silicon nitride film. According to the above structure, thebuffer layer is formed, so that the impurities (In, Sn, etc.) can beprevented from mixing therein from the transparent conductive film and asuperior protective film having no impurities can be formed.

With such a structure, it is possible to improve reliability as well asto protect the light emitting element.

Also, FIG. 4B is a schematic diagram showing another example of thelaminate structure of the EL element. In FIG. 4B, reference numeral 300denotes a cathode (or an anode); 301, an EL layer; 302, an anode (or acathode); 303, a silicon nitride film containing hydrogen; and 304, aprotective film. When the emitted light is caused to pass through theanode 302, it is preferable to form the anode 302 using a conductivematerial having a light-transmissive property, an extremely thin metalfilm (MgAg), or a laminate thereof.

Also, when the emitted light is caused to pass through the anode 302, asthe anode 302, a conductive film (ITO, ZnO, etc.) having alight-transmissive property is preferably used. Further, as the cathode300, a metal film (an alloy film of MgAg, MgIn, AlLi, etc. or a filmformed by coevaporation of aluminum and an element belonging to Group 1or 2 in the periodic table) or a laminate thereof is preferably used.

The protective film 304 may be made of an insulating film mainlycontaining silicon nitride or silicon oxynitride which is obtained by asputtering method (DC system or RF system). The silicon nitride film maybe obtained by using a silicon target through the formation in anatmosphere containing nitrogen and argon. Also, a silicon nitride targetcan be used. The protective film 304 may be also formed by a filmformation apparatus using a remote plasma. Further, when the emittedlight is caused to pass through the protective film, it is preferablethat the protective film is made as thin as possible.

The silicon nitride film 303 containing hydrogen may be formed by aplasma CVD method (typically, RF plasma CVD method, microwave CVDmethod, electron cyclotron resonance (ECR) CVD method, or the like), anRF sputtering method, a DC sputtering method, or the like.

As a method of forming the silicon nitride film 303 containing hydrogen,the film is formed within a range of temperature to which the organiccompound layer can be resistant, for example, a range from roomtemperature to 100° C. or less.

When the plasma CVD method is used as the forming method for the siliconnitride film 303 containing hydrogen, as a reaction gas, a gascontaining nitrogen (nitrogen oxide-based gas represented by N₂ andNH₃NO_(x) or the like) and a hydrogen silicide-based gas (e.g., silane(SiH₄), disilane, trisilane, etc.) may be used.

When the sputtering method is used as the forming method for the siliconnitride film 303 containing hydrogen, a silicon nitride film containinghydrogen may be obtained by using a silicon target through the formationin an atmosphere containing hydrogen, nitrogen, and argon. Also, asilicon nitride target may be used.

Heat treatment is performed within a range of temperature to which theorganic compound layer can be resistant and heat generated when thelight emitting element emits the light is utilized, so that hydrogen canbe diffused from the silicon nitride film containing hydrogen toterminate defects in the organic compound layer with hydrogen(termination). By terminating the defects in the organic compound layerwith hydrogen, the light emitting device is increased in itsreliability. Also, when the silicon nitride film containing hydrogen isformed, hydrogen turned into a plasma can be used to terminate thedefects in the organic compound layer with hydrogen. In addition, theprotective film formed so as to cover the silicon nitride filmcontaining hydrogen functions to block hydrogen diffused toward theprotective film side and to efficiently diffuse hydrogen into theorganic compound layer to thereby terminate defects in the organiccompound layer with hydrogen as well. Note that, the silicon nitridefilm containing hydrogen can also serve as the protective film for thelight emitting element.

Further, the silicon nitride film containing hydrogen can serve as abuffer layer as well. When the silicon nitride film is formed in contactwith the film made of the transparent conductive film by a sputteringmethod, there is a possibility that impurities (In, Sn, Zn, etc.)contained in the transparent conductive film are mixed into the siliconnitride film. However, by forming the silicon nitride film containinghydrogen as a buffer layer therebetween, it is also possible to preventmixture of the impurities into the silicon nitride film. According tothe above structure, the buffer layer is formed, so that the impurities(In, Sn, etc.) can be prevented from mixing therein from the transparentconductive film and a superior protective film having no impurities canbe formed.

With such a structure, it is possible to improve reliability as well asto protect the light emitting element.

Also, FIGS. 4A and 4B show an example in which the film containinghydrogen is provided as a single layer, but the film may be a laminateconsisting of the silicon nitride film containing hydrogen and the DLCfilm containing hydrogen or a laminate thereof having three or morelayers.

Further, this embodiment mode can be applied not only to an activematrix display device but also to a passive display device.

Also, this embodiment mode can be freely combined with Embodiment Mode1.

Embodiment Mode 3

Here, FIGS. 6A to 6C show an example of a structure partially differentfrom FIGS. 1A to 1C. In this example, among a number of pixels arrangedregularly in the pixel portion, pixels in a 3×3 matrix are used by wayof example and the present invention will be described below. Note that,in a sectional structure, TFTs of FIGS. 6A to 6C are substantially thesame as those of FIGS. 1A to 1C and thus components identical to thoseof FIGS. 1A to 1C are denoted by identical reference numerals forsimplicity.

FIG. 6A is a sectional view taken along the alternate long and shortdash line A-A′ of FIG. 5A. A light emitting region 50R indicates a redlight emitting region; a light emitting region 50G, a green lightemitting region; and a light emitting region 50B, a blue light emittingregion. These light emitting regions of three colors realize a lightemitting display device capable of full color display.

As shown in FIG. 6A, this embodiment mode employs an example in whichpatterning is performed using the same mask. Thus, an auxiliaryelectrode 621 and an organic insulator 624 have substantially the sameshape as viewed from the above. In this case, as shown in FIG. 6C, theauxiliary electrode 621 is electrically connected to the wiring made ofthe same material as a source wiring through the cathode 20.

Also, the pixel electrode 612 (612 a to 612 c) is formed on theinterlayer insulating film 15 and contact holes of the TFTs are formedafter the pixel electrode 612 is formed, through which electrodes 607and 608 subsequently formed electrically connect the pixel electrode 612and the TFTs. The inorganic insulating films 14 cover both ends of thepixel electrodes and portions therebetween. Also, similarly to FIGS. 1Ato 1C, the organic compound layer is formed so as to partially cover theorganic insulator 624.

FIG. 5B is a top view showing a pixel electrode immediately after itsformation, which corresponds to FIG. 5A. In FIGS. 5A and 5B, the organiccompound layer is provided for each pixel column (Y direction). Theorganic insulator 624 in a strip shape is provided between the organiccompound layers differing from each other in color of the emitted lightin a strip shape. Also, in FIG. 5A, the organic insulator 624 and theauxiliary electrode 621 are provided for each pixel column (Ydirection).

FIG. 7A is a top view corresponding to FIGS. 5A to 6C. In FIG. 7A, theconnection portion in the left-hand portion is partially shown in theright-hand portion in section, which corresponds to the portion shown inFIG. 6C. Further, when the auxiliary electrode 621 and the organicinsulator of FIG. 7A are subjected to patterning, a metal mask shown inFIG. 8A as an example is used therefor.

Also, when the film thickness in total of the organic insulator and theauxiliary electrode is relatively large, steps are increased, so thatthere is a possibility that the transparent conductive film is difficultto use for electrical connection. In particular, in the case where thetransparent conductive film is made thin, a line defect may occur due toa poor coverage. Therefore, in order to further ensure connectionbetween the auxiliary electrode 621 and the electrode on the lowerlayer, as shown in FIG. 7B, the number of masks may be increased to formelectrodes denoted by 622. Also, the metal mask may be used to form theelectrodes 622 by an evaporation method.

In addition, as shown in FIG. 7C, a wiring 623 made of the same materialas the source wiring is formed in advance so as to surround the pixelportion. Following this, second auxiliary electrodes 624 may be formedso as to intersect the auxiliary electrodes 621 at right angles. Withthis arrangement, each second auxiliary wiring 624 can be provided so asto directly contact the wiring 623 as well as the auxiliary electrode621. Here, the auxiliary electrode 621 and the second auxiliaryelectrode 624 are designed such that a portion therebetween serves asthe light emitting region as appropriate. Also, when the secondauxiliary electrode 624 of FIG. 7A is subjected to patterning, a metalmask shown in FIG. 8B as an example is used therefor.

Further, FIG. 7C shows an example in which patterning is performed twiceto form the first auxiliary electrode 621 and the second auxiliaryelectrode 624. However, the auxiliary electrodes may be formed in alattice shape using the metal mask shown in FIG. 8C. As shown in aright-hand portion of FIG. 8C, openings are divided along the thin line.At the time of evaporation, there is a wrap-around portion, whichpartially makes a film thin, but the auxiliary electrodes can be formedin a lattice shape.

Also, this embodiment mode can be freely combined with Embodiment Mode 1or 2.

Embodiment Mode 4

Here, an example of a structure partially different from FIGS. 1A to 1Cis shown in FIGS. 9A to 9C. In this example, among a number of pixelsarranged regularly in the pixel portion, pixels in a 3×3 matrix are usedby way of example and the present invention will be described below.Note that, in a sectional structure, the structure is substantially thesame as those of FIGS. 1A to 1C except that the organic insulator 24 isnot provided and an organic compound layer 60 made of a polymer isprovided on the entire surface. Thus, in FIGS. 9A to 9C, componentsidentical to those of FIGS. 1A to 1C are denoted by identical referencenumerals for simplicity. Also, FIG. 9A is a sectional view taken alongthe dashed line A-A′ of FIG. 2.

Instead of providing in the structure of FIGS. 9A to 9C the organicinsulator 24 shown in FIGS. 1A to 1C, the inorganic insulating films 14and auxiliary electrodes 721 serve to maintain the intervals among theorganic compounds 17, 18, and 19.

Also, the organic compound layer 60 made of a polymer (typically,poly(ethylene dioxythiophene)/poly(styrene sulfonate) aqueous solution(hereinafter, referred to as “PEDOT/PSS”) which serves as a holeinjection layer for reference's sake) is formed by a coating method suchas a spin coating method or a spray method and thus is formed on theentire surface. Also, the organic compound layer 60 made of a polymerhas conductivity, through which electrical connection between thecathode 20 and the auxiliary electrode 721 is achieved. By providing theauxiliary electrode 721, the cathode (or the anode) can be decreased inresistance in its entirety. In addition, the transparent conductive filmcan be made thin. Further, the auxiliary electrode 721 is used toachieve connection with the wiring or electrode in the lower layer. Theauxiliary electrode 721 may be subjected to film formation or patterningbefore the EL layer is formed. If the transparent conductive film isformed on the auxiliary electrode 721 brought into contact with theelectrode in the lower layer, the cathode can be led out. Note that,FIG. 9C is a sectional view taken along the dashed line C-C′ of FIG. 2.Further, in FIG. 9C, electrodes connected by the dotted line areelectrically connected to each other. In the terminal portion, theelectrode of the terminal is formed of the same material as the cathode20.

Further, FIG. 9B is a sectional view taken along the dashed line B-B′ ofFIG. 2. Also in FIG. 9B, the inorganic insulating films 14 cover bothends of portions denoted by 11 a to 11 c and regions therebetween. Inthis case, although an example in which an EL layer 17 emitting a redlight is used in common is shown, the present invention is notparticularly limited to the above. It may be also possible to form theEL layer for each pixel emitting the same color.

Further, this embodiment mode can be freely combined with one ofEmbodiment Mode 1 to Embodiment Mode 3.

Embodiment Mode 5

Here, an example of a structure partially different from FIGS. 1A to 1Cis shown in FIGS. 10A to 10C. In this example, among a number of pixelsarranged regularly in the pixel portion, pixels in a 3×3 matrix are usedby way of example and the present invention will be described below.Note that, in a sectional structure, the structure is substantially thesame as those of FIGS. 1A to 1C except that auxiliary wirings 821 areprovided on the cathode 20. Thus, in FIGS. 10A to 10C, componentsidentical to those of FIGS. 1A to 1C are denoted by identical referencenumerals for simplicity. Also, FIG. 10A is a sectional view taken alongthe dashed line A-A′ of FIG. 2.

Also, the auxiliary electrodes 821 are formed on the cathode and thus isformed by an evaporation method using the metal mask. In this case, anexample in which the auxiliary electrode 821 is formed in a latticeshape. By providing the auxiliary electrode 821, the cathode (or theanode) can be decreased in resistance in its entirety. In addition, thetransparent conductive film can be made thin. Further, the auxiliaryelectrode 821 is used to achieve connection with the wiring or electrodein the lower layer. If the transparent conductive film is formed on theauxiliary electrode 821 brought into contact with the electrode in thelower layer, the cathode can be led out. Note that, FIG. 10C is asectional view taken along the dashed line C-C′ of FIG. 2. Further, inFIG. 10C, electrodes connected by the dotted line are electricallyconnected to each other. In the terminal portion, the electrode of theterminal is formed of the same material as the cathode 20.

Further, this embodiment mode can be freely combined with one ofEmbodiment Mode 1 to Embodiment Mode 4.

The present invention thus structured will be further described usingthe following embodiments in detail.

Embodiment 1

In this embodiment, the active matrix type light emitting device formedon the insulating surface is described. As an active element, a thinfilm transistor is used (hereinafter referred to as TFT) here, a MOStransistor may also be used.

A top gate TFT (specifically a planar TFT) is shown as an example, abottom gate TFT (typically inverse staggered TFT) may also be used.

In this embodiment, a glass substrate is used, which is made of bariumborosilicate glass or aluminoborosilicate glass, a quartz substrate, asilicon substrate, a metal substrate, or stainless substrate forming aninsulating film on the surface may be used as a substrate. A plasticsubstrate having heat resistance enduring a treatment temperature ofthis embodiment also may be used, and further a flexible substrate maybe used.

Next, a silicon oxynitride film is formed as a lower layer of a baseinsulating film on a heat-resistant glass substrate with a thickness of0.7 mm by plasma CVD at a temperature of 400° C. using SiH₄, NH₃, andN₂O as material gas (the composition ratio: Si=32%, O=27%, N=24%,H=17%). The silicon oxynitride film has a thickness of 50 nm (preferably10 to 200 nm). The surface of the film is washed with ozone water andthen an oxide film on the surface is removed by diluted fluoric acid(diluted down to {fraction (1/100)}). Next, a silicon oxynitride film isformed as an upper layer of the base insulating film by plasma CVD at atemperature of 400° C. using SiH₄ and N₂O as material gas (thecomposition ratio: Si=32%, O=59%, N=7%, H=2%). The silicon oxynitridefilm has a thickness of 100 nm (preferably 50 to 200 nm) and is laid onthe lower layer to form a laminate. Without exposing the laminate to theair, a semiconductor film having an amorphous structure (here, anamorphous silicon film) is formed on the laminate by plasma CVD at atemperature of 300° C. using SiH₄ as material gas. The semiconductorfilm (an amorphous silicon film is used here) is 54 nm (preferably 25 to200 nm) in thickness.

A base insulating film in this embodiment has a two-layer structure.However, the base insulating film may be a single layer or more than twolayers of insulating films mainly containing silicon. The material ofthe semiconductor film is not limited but it is preferable to form thesemiconductor film from silicon or a silicon germanium alloy(Si_(x)Ge_(1-X) (X=0.0001 to 0.02)) by a known method (sputtering,LPCVD, plasma CVD, or the like). Plasma CVD apparatus used may be onethat processes wafer by wafer or one that processes in batch. The baseinsulating film and the semiconductor film may be formed in successionin the same chamber to avoid contact with the air.

The surface of the semiconductor film having an amorphous structure iswashed and then a very thin oxide film, about 2 nm in thickness, isformed on the surface using ozone water. Next, the semiconductor film isdoped with a minute amount of impurity element (boron or phosphorus) inorder to control the threshold of the TFTs. Here, the amorphous siliconfilm is doped with boron by ion doping in which diborane (B₂H₆) isexcited by plasma without mass separation. The doping conditions includesetting the acceleration voltage to 15 kV, the flow rate of gas obtainedby diluting diborane to 1% with hydrogen to 30 sccm, and the dose to2×10¹² atoms/cm².

Next, a nickel acetate solution containing 10 ppm of nickel by weight isapplied by a spinner. Instead of application, nickel may be sprayed ontothe entire surface by sputtering.

The semiconductor film is subjected to heat treatment to crystallize itand obtain a semiconductor film having a crystal structure. The heattreatment is achieved in an electric furnace or by irradiation ofintense light. When heat treatment in an electric furnace is employed,the temperature is set to 500 to 650° C. and the treatment lasts for 4to 24 hours. Here, a silicon film having a crystal structure is obtainedby heat treatment for crystallization (at 550° C. for 4 hours) afterheat treatment for dehydrogenation (at 500° C. for an hour). Althoughthe semiconductor film is crystallized here by beat treatment using anelectric furnace, it may be crystallized by a lamp annealing apparatuscapable of achieving crystallization in a short time.

After an oxide film on the surface of the silicon film having a crystalstructure is removed by diluted fluoric acid or the like, a continuouswave solid-state laser and the second to fourth harmonic of thefundamental wave are employed in order to obtain crystals of large grainsize when crystallizing an amorphous semiconductor film. Since the laserlight irradiation is conducted in the air or in an oxygen atmosphere, anoxide film is formed on the surface as a result. Typically, the secondharmonic (532 nm) or third harmonic (355 nm) of a Nd:YVO₄ laser(fundamental wave: 1064 nm) is employed. When using a continuous wavelaser, laser light emitted from a 10 W power continuous wave YVO₄ laseris converted into harmonic by a non-linear optical element.Alternatively, the harmonic is obtained by putting a YVO₄ crystal and anon-linear optical element in a resonator. The harmonic is preferablyshaped into oblong or elliptical laser light on an irradiation surfaceby an optical system and then irradiates an irradiation object. Theenergy density required at this point is about 0.01 to 100 MW/cm²(preferably 0.1 to 10 MW/cm²). During the irradiation, the semiconductorfilm is moved relative to the laser light at a rate of 10 to 2000 cm/s.

Of course, although a TFT can be formed by using the silicon film havinga crystallizing structure before the second harmonics of the continuouswave YVO₄ laser is irradiated thereon, it is preferable that the siliconfilm having a crystalline structure after the laser light is irradiatedthereon is used to form the TFT since the silicon film irradiated thelaser light thereon has an improved crystallinity and electriccharacteristics of TFT are improved. For instance, although, when TFT isformed by using the silicon film having a crystalline structurebefore-the laser light is irradiated thereon, a mobility is almost 300cm²/Vs, when TFT is formed by using the silicon film having acrystalline structure after the laser light is irradiated thereon, themobility is extremely improved with about 500 to 600 cm²/Vs.

After the crystallization is conducted using nickel as a metal elementthat promotes crystallization of silicon, the second harmonic of thecontinuous wave YVO₄ laser is irradiated thereon though, not limitedthereof, after the silicon film is formed having an amorphous structureand the heat treatment is performed for dehydrogenation, and the siliconfilm having a crystalline structure may be obtained by the secondharmonics of the continuous wave YVO₄ laser may be irradiated.

The pulse wave laser may be used for as a substitute of the continuouswave laser. In the case that the excimer laser of the pulse wave isused, it is preferable that the frequency is set to 300 Hz, and thelaser density is set from 100 to 1000 mJ/cm² (typically 200 to 800mJ/cm²). Here, the laser light may be overlapped 50 to 98%.

In addition to the oxide film formed by laser light irradiation, thesurface is treated with ozone water for 120 seconds to form as a barrierlayer an oxide film having a thickness of 1 to 5 nm in total. Thebarrier layer here is formed using ozone water but it may be formed byoxidizing the surface of the semiconductor film having a crystalstructure through ultraviolet irradiation in an oxygen atmosphere, orformed by oxidizing the surface of the semiconductor film having acrystal structure through oxygen plasma treatment, or by using plasmaCVD, sputtering or evaporation to form an about 1 to 10 nm thick oxidefilm. The oxide film formed by the laser light irradiation may beremoved before the barrier layer is formed.

Next, an amorphous silicon film containing argon is formed on thebarrier layer by plasma CVD or sputtering to serve as a gettering site.The thickness of the amorphous silicon film is 50 to 400 nm, here 150nm. The amorphous silicon film is formed in an argon atmosphere with thefilm formation pressure to 0.3 Pa by sputtering using the silicontarget.

Thereafter, heat treatment is conducted in an electric furnace at 650°C. for 3 minutes for gettering to reduce the nickel concentration in thesemiconductor film having a crystal structure. Lamp annealing apparatusmay be used instead of an electric furnace.

Using the barrier layer as an etching stopper, the gettering site,namely, the amorphous silicon film containing argon, is selectivelyremoved. Then, the barrier layer is selectively removed by dilutedfluoric acid. Nickel tends to move toward a region having high oxygenconcentration during gettering, and therefore it is desirable to removethe barrier layer that is an oxide film after gettering.

Next, a thin oxide film is formed on the surface of the obtained siliconfilm containing a crystal structure (also referred to as a polysiliconfilm) using ozone water. A resist mask is then formed and the siliconfilm is etched to form island-like semiconductor layers separated fromone another and having desired shapes. After the semiconductor layersare formed, the resist mask is removed.

The oxide film is removed by an etchant containing fluoric acid, and atthe same time, the surface of the silicon film is washed. Then, aninsulating film mainly containing silicon is formed to serve as a gateinsulating film. The gate insulating film here is a silicon oxynitridefilm (composition ratio: Si=32%, O=59%, N=7%, H=2%) formed by plasma CVDto have a thickness of 115 nm.

Next, a laminate of a first conductive film with a thickness of 20 to100 nm and a second conductive film with a thickness of 100 to 400 nm isformed on the gate insulating film. In this embodiment, a tantalumnitride film with a thickness of 50 nm is formed on the gate insulatingfilm and then a tungsten film with a thickness of 370 nm is laidthereon. The conductive films are patterned by the procedure shown belowto form gate electrodes and wirings.

The conductive materials of the first conductive film and secondconductive film are elements selected from the group consisting of Ta,W, Ti, Mo, Al, and Cu, or alloys or compounds mainly containing theabove elements. The first conductive film and the second conductive filmmay be semiconductor films, typically polycrystalline silicon films,doped with phosphorus or other impurity elements or may be Ag—Pd—Cualloy films. The present invention is not limited to a two-layerstructure conductive film. For example, a three-layer structureconsisting of a 50 nm thick tungsten film, 500 nm thick aluminum-siliconalloy (Al—Si) film, and 30 nm thick titanium nitride film layered inthis order may be employed. When the three-layer structure is employed,tungsten of the first conductive film may be replaced by tungstennitride, the aluminum-silicon alloy (Al—Si) film of the secondconductive film may be replaced by an aluminum-titanium alloy (Al—Ti)film, and the titanium nitride film of the third conductive film may bereplaced by a titanium film. Alternatively, a single-layer conductivefilm may be used.

ICP (Inductively Coupled Plasma) etching is preferred for etching of thefirst conductive film and second conductive film (first etchingtreatment and second etching treatment). By using ICP etching andadjusting etching conditions (the amount of electric power applied to acoiled electrode, the amount of electric power applied to a substrateside electrode, the temperature of the substrate side electrode, and thelike), the films can be etched and tapered as desired. The first etchingtreatment is conducted after a resist mask is formed. The first etchingconditions include applying an RF (13.56 MHz) power of 700 W to a coiledelectrode at a pressure of 1 Pa, employing CF₄, Cl₂, and O₂ as etchinggas, and setting the gas flow rate ratio thereof to 25/25/10 (sccm). Thesubstrate side (sample stage) also receives an RF power of 150 W (13.56MHz) to apply a substantially negative self-bias voltage. The area(size) of the substrate side electrode is 12.5 cm×12.5 cm and the coiledelectrode is a disc 25 cm in diameter (here, a quartz disc on which thecoil is provided). The W film is etched under these first etchingconditions to taper it around the edges. Thereafter, the first etchingconditions are switched to the second etching conditions withoutremoving the resist mask. The second etching conditions include usingCF₄ and Cl₂ as etching gas, setting the gas flow rate ratio thereof to30/30 (sccm), and giving an RF (13.56 MHz) power of 500 W to a coiledelectrode at a pressure of 1 Pa to generate plasma for etching for about30 seconds. The substrate side (sample stage) also receives an RF powerof 20 W (13.56 MHz) to apply a substantially negative self-bias voltage.Under the second etching conditions where a mixture of CF₄ and Cl₂ isused, the W film and the TaN film are etched to almost the same degree.The first etching conditions and the second etching conditionsconstitute the first etching treatment.

Next follows the second etching treatment with the resist mask kept inplace. The third etching conditions include using CF₄ and Cl₂ as etchinggas, setting the gas flow rate ratio thereof to 30/30 (sccm), and givingan RF (13.56 MHz) power of 500 W to a coiled electrode at a pressure of1 Pa to generate plasma for etching for 60 seconds. The substrate side(sample stage) also receives an RF power of 20 W (13.56 MHz) to apply asubstantially negative self-bias voltage. Then, the third etchingconditions are switched to the fourth etching conditions withoutremoving the resist mask. The fourth etching conditions include usingCF₄, Cl₂, and O₂ as etching gas, setting the gas flow rate ratio thereofto 20/20/20 (sccm), and giving an RF (13.56 MHz) power of 500 W to acoiled electrode at a pressure of 1 Pa to generate plasma for etchingfor about 20 seconds. The substrate side (sample stage) also receives anRF power of 20 W (13.56 MHz) to apply a substantially negative self-biasvoltage. The third etching conditions and the fourth etching conditionsconstitute the second etching treatment. At this stage, gate electrodeand wirings having the first conductive layer as the lower layer and thesecond conductive layer as the upper layer are formed.

Next, the resist mask is removed for the first doping treatment to dopewith the entire surface using the gate electrodes as masks. The firstdoping treatment employs ion doping or ion implantation. Here, iondoping conditions are that the dose is set to 1.5×10¹⁴ atoms/cm², andthe acceleration voltage is set from 60 to 100 keV. As an impurityelements that imparts the n-type conductivity, phosphorus (P) or arsenic(As) is typically used. The first impurity regions (n⁻⁻ region) areformed in a self-aligning manner.

Masks formed from resist are newly formed. At this moment, since the offcurrent value of the switching TFT is lowered, the masks are formed tooverlap the channel formation region of a semiconductor layer formingthe switching TFT of the pixel portion, and a portion thereof. The masksare formed to protect the channel formation region of the semiconductorlayer forming the p-channel TFT of the driver circuit and the peripherythereof. In addition, the masks are formed to overlap the channelformation region of the semiconductor layer forming the current controlTFT of the pixel portion and the periphery thereof.

An impurity region (n⁻ region) that overlaps with a portion of the gateelectrode is formed by conducting selectively the second dopingtreatment using the masks from the resist. The second doping treatmentis employs ion doping or ion implantation. Here, ion doping is used, theflow rate of gas obtained by diluting phosphine (PH₃) with hydrogen to5% is set to 30 sccm, the dose is set to 1.5×10¹⁴ atoms/cm², and theacceleration voltage is set to 90 keV. In this case the masks made fromresist and the second conductive layer serve as masks against theimpurity element that imparts the n-type conductivity and secondimpurity regions are formed. The second impurity regions are doped withthe impurity element that imparts the n-type conductivity in aconcentration range of 1×10¹⁶ to 1×10¹⁷ atoms/cm³. Here, the sameconcentration range as the second impurity region is referred to as a n⁻region.

Third doping treatment is conducted without removing the resist masks.The third doping treatment employs ion doping or ion implantation. Asimpurity elements imparts n-type conductivity, phosphorus (P) or arsenic(As) are used typically. Here, ion doping is used, the flow rate of gasobtained by diluting phosphine (PH₃) with hydrogen to 5% is set to 40sccm, the dose is set to 2×10¹⁵ atoms/cm², and the acceleration voltageis set to 80 keV. In this case the masks made from resist and the secondconductive layer serve as masks against the impurity element thatimparts the n-type conductivity and third impurity regions are formed.The third impurity regions are doped with the impurity element thatimparts the n-type conductivity in a concentration range of 1×10²⁰ to1×10²¹ atoms/cm³. Here, the same concentration range as the thirdimpurity region is referred to as a n⁺ region.

After removing the resist mask and the new resist mask is formed, thefourth doping treatment is conducted. The fourth impurity regions andthe fifth impurity regions are formed in which impurity elements impartsp-type conductivity are added to the semiconductor layer forming thep-channel TFT by the fourth doping treatment.

The concentration of the impurity element that imparts the p-typeconductivity is set from 1×10²⁰ to 1×10²¹ atoms/cm³ to add to the fourthimpurity regions. The fourth impurity regions being region (n⁻⁻ region)are already doped with phosphorus (P) in the previous step but are dopedwith the impurity element that imparts the p-type conductivity in aconcentration 1.5 to 3 times the phosphorus concentration to obtain thep-type conductivity. Here, a region having the same concentration rangeas the fourth impurity regions is also called a p⁺ region.

The fifth impurity regions are formed in the region overlaps with thetaper portion of the second conductive layer. The impurity elementsimparts p-type conductivity is added thereto at the concentration rangefrom 1×10¹⁸ to 1×10²⁰ atoms/cm³. Here, the region having the sameconcentration range as the fifth impurity regions is also referred to asp⁻ region.

Through the above steps, an impurity region having the n-type or p-typeconductivity is formed in each semiconductor layer. The conductivelayers become the gate electrode of TFT.

An insulating film is formed to cover almost the entire surface (notshown). In this embodiment, the silicon oxide film having 50 nm inthickness is formed by plasma CVD method. Of course, the insulating filmis not limited to a silicon oxide film and a single layer or laminate ofother insulating films containing silicon may be used.

The next step is activation treatment of the impurity elements used todope the semiconductor layers. The activation step employs rapid thermalannealing (RTA) using a lamp light source, irradiation of a laser, heattreatment using a furnace, or a combination of these methods.

In the example shown in this embodiment, the interlayer insulating filmis formed after the above-described activation. However, the insulatingfilm may be formed before the activation.

The first interlayer insulating film made from a silicon nitride film isformed. Then, the semiconductor layers are subjected to heat treatment(at 300 to 550° C. for 1 to 12 hours) to hydrogenate the semiconductorlayers. This step is for terminating dangling bonds in the semiconductorlayers using hydrogen contained in the first interlayer insulating film.The semiconductor layers are hydrogenated irrespective of the presenceof the interlayer insulating film that is a silicon oxide film. Otherhydrogenation methods employable include plasma hydrogenation (usinghydrogen excited by plasma).

Next, a second interlayer insulating film is formed on the firstinterlayer insulating film from an organic insulating material. In thisembodiment, an acrylic resin film is formed to have a thickness of 1.6μm by application method.

Formed next are contact holes reaching the conductive layers that serveas the gate electrodes or gate wirings and contact holes reaching theimpurity regions. In this embodiment, etching treatment is conductedseveral times in succession. Also, in this embodiment, the firstinterlayer insulating film is used as an etching stopper to etch thesecond interlayer insulating film, and then the first interlayerinsulating film is etched.

Thereafter, electrodes, specifically, a source wiring, a power supplyline, a lead-out electrode, a connection electrode, etc. are formed fromAl, Ti, Mo, or W. Here, the electrodes and wirings are obtained bypatterning a laminate of a Ti film (100 nm in thickness), an Al filmcontaining silicon (350 nm in thickness), and another Ti film (50 nm inthickness). The source electrode, source wiring, connection electrode,lead-out electrode, power supply line, and the like are thus formed asneeded. A lead-out electrode for the contact with a gate wiring coveredwith an interlayer insulating film is provided at an end of the gatewiring, and other wirings also have at their ends input/output terminalportions having a plurality of electrodes for connecting to externalcircuits and external power supplies. A driving circuit having a CMOScircuit in which an n-channel TFT and a p-channel TFT are combinedcomplementarily and a pixel portion with a plurality of pixels eachhaving an n-channel TFT or a p-channel TFT are formed in the mannerdescribed above.

Next, the third interlayer insulating film made of inorganic insulatingmaterial is formed on the second interlayer insulating film. In thisembodiment, the silicon nitride film with a thickness of 200 nm isformed by sputtering.

Next, a contact hole that reaches the connection electrode that contactswith the drain region of the current control TFT by p-channel type TFTis formed. Next, the pixel electrode is formed with connecting andoverlapping the TFT connection electrode. In this embodiment, thematerials with a large work function, concretely platinum (Pt), chrome(Cr), tungsten (W), nickel (Ni), because the pixel electrode is made tofunction as an anode of an organic light emitting element.

Next, inorganic insulators are formed at both ends to cover the edge ofthe pixel electrode. Inorganic insulators with covering the edge ofpixel electrode are made with the insulating film containing silicon bysputtering and then performed patterning. Instead of insulators, a bankcomposed of organic materials may be formed.

Next, a supporting electrode is formed on the inorganic insulators asshown in Embodiment Mode 1.

Next, EL layer and a cathode of an organic light emitting element areformed on the pixel electrode of which both edges are covered byinorganic insulators. Inc jet method, evaporation method, spin coatingmethod and the like may be used for forming the EL layer.

An EL layer (a layer for light emission and for moving of carriers tocause light emission) has a light emitting layer and a free combinationof electric charge transporting layers and electric charge injectionlayers. For example, a low molecular weight organic EL material or ahigh molecular weight organic EL material is used to form an EL layer.An EL layer may be a thin film formed of a light emitting material thatemits light by singlet excitation (fluorescence) (a singlet compound) ora thin film formed of a light emitting material that emits light bytriplet excitation (phosphorescence) (a triplet compound). Inorganicmaterials such as silicon carbide may be used for the electric chargetransporting layers and electric charge injection layers. Known organicEL materials and inorganic materials can be employed.

Also, it is assumed as being preferable that as a material for thecathode, metals having a low work function (typically, metal elementsbelonging to Group 1 or Group 2 in the periodic table) or alloyscontaining these are used. As the work function becomes lower, the lightemission efficiency becomes higher. Thus, in particular, it is desirablethat a material with a laminate structure is used as the material forthe cathode, which is obtained by depositing an alloy of MgAg, MgIn,AlLi, etc. into a thin film or forming a thin film through coevaporationof aluminum and an element belonging to Group 1 or 2 in the periodictable, and subsequently forming a transparent conductive film (an alloyof an indium oxide and a tin oxide (ITO), an alloy of an indium oxideand a zinc oxide (In₂O₃—ZnO), an zinc oxide (ZnO), and the like).

Next, the protective film covering the cathode is formed. The protectivefilm may be formed of an insulating film mainly containing siliconnitride or silicon oxynitride by a sputtering method. As shown inEmbodiment Mode 2, the defects in the EL layer are terminated withhydrogen (termination) and thus, it is preferable to form the filmcontaining hydrogen on the cathode.

The film containing hydrogen may be formed of an insulating film mainlycontaining carbon or silicon nitride by a PCVD method. At the time offilm formation, it is also possible to terminate the defects in theorganic compound layer with hydrogen turned into a plasma. Heattreatment is performed within a range of temperature to which theorganic compound layer can be resistant and heat generated when thelight emitting element emits light is utilized, so that hydrogen can bediffused from the film containing hydrogen to terminate defects in theorganic compound layer with hydrogen (termination).

Also, the film containing hydrogen and the protective film are used toprevent from entering from the outside the substance such as moisture oroxygen which causes deterioration of the EL layer due to oxidation. Notethat, in an input/output terminal portion to be connected with the FPClater, there is not required to provide the protective film, the filmcontaining hydrogen, and the like.

Also, various circuits composed of a plurality of TFTs etc. may beprovided to lead to the gate electrode of the TFT arranged in the pixelportion. Needless to say, there is not imposed a particular limitationthereon.

Next, the organic light emitting element including at least the cathode,the organic compound layer, and the anode is enclosed by the sealingsubstrate or a sealing can. Thus, the organic light emitting element ispreferably blocked from the outside completely to prevent from enteringfrom the outside the substance such as moisture or oxygen which causesdeterioration of the EL layer due to oxidation. It is preferable thatdegassing is performed by annealing in the vacuum immediately beforeenclosure with the sealing substrate or the sealing can. Also, when thesealing substrate is bonded to the substrate, it is preferable that theprocedure is performed in an atmosphere containing hydrogen and inertgas (rare gas or nitrogen) and a space sealed by sealing containshydrogen. Heat generated when the light emitting element emits a lightis utilized, which makes it possible to diffuse hydrogen from the spacecontaining hydrogen to thereby terminate defects in the organic compoundlayer with hydrogen. By terminating the defects in the organic compoundlayer with hydrogen, the light emitting device can be increased in itsreliability.

Subsequently, an FPC (flexible printed circuit) is bonded to eachelectrode in the input/output terminal portion by using an anisotropicconductive member. The anisotropic conductive member consists of resinand conductive particles having a particle size of several tens toseveral hundreds of μm with its surface plated with Au or the like. Theconductive particles serve to electrically connect each electrode of theinput/output terminal portion and the wiring formed on the FPC.

Also, the substrate is provided with the color filters corresponding tothe respective pixels and then, provision of the color filters makes acircular polarization plate unnecessary. Further, another optical filmmay be provided if necessary and an IC chip etc. may be mounted thereon.

Through the above steps, the modularized light emitting device connectedwith the FPC is completed.

Further, this embodiment can be freely combined with one of EmbodimentMode 1 to Embodiment Mode 5.

Embodiment 2

In this embodiment, a manufacturing apparatus will be shown withreference to FIG. 11.

In FIG. 11, reference symbols 100 a to 100 k, and 100 m to 100 v eachdenote a gate; 101 and 109, a delivery chamber; 102, 104 a, 107, 108,111, and 114, a transportation chamber; 105, 106R, 106B, 106G, 106H,109, 110, 112, and 113, a film formation chamber; 103, a pretreatmentchamber; 117 a and 117 b, a sealing substrate loading chamber; 115, adispenser chamber; 116, a sealing chamber; 118 a, a ultravioletirradiating chamber; and 120, a substrate inverting chamber.

Hereinafter, the substrate previously having formed the TFT thereon iscarried in the manufacturing apparatus shown in FIG. 11. Here, aprocedure for forming a laminate structure shown in FIG. 4A isexplained.

First, the substrate is set in the delivery chamber 101, on which theTFT and the cathode (or the anode) 200 are formed, and is thentransported to the transportation chamber 102 connected to the deliverychamber 101. It is preferable that vacuum-exhausting is conducted on thetransportation chamber to attain an atmospheric pressure by introducingthe inert gas in advance such that the moisture or oxygen in thetransportation chamber is suppressed to as low level as possible.

Also, the transportation chamber 102 is connected to a vacuum exhaustingprocessing chamber for making the inside of the transportation chambervacuum. The vacuum exhausting processing chamber is equipped with amagnetic levitation type turbo molecular pump, a cryopump, or a drypump. With this structure, it is possible that the ultimate vacuum ofthe transportation chamber is set to 10⁻⁵ to 10⁻⁶ Pa and the impurity iscontrolled so as not to diffuse backward from the pump side orexhausting system. In order to prevent the introduction of the impurityinto the inside of the apparatus, as a gas to be introduced, an inertgas such as nitrogen or a rare gas is used. These gases introduced tothe inside of the apparatus are required to be highly purified by a gaspurifier prior to the introduction into the apparatus when they areused. Accordingly, it is necessary to provide the gas purifier in orderto introduce into the film formation apparatus the gas after beinghighly purified. Thus, the oxygen or moisture contained in the gas andother impurities can be eliminated in advance, so that it is possible toprevent such impurities from being introduced to the inside of theapparatus.

Also, in order to eliminate the moisture or other gases contained in thesubstrate, it is preferable to perform annealing for degassing in thevacuum. Therefore, the substrate is transported to the pretreatmentchamber 103 connected to the transportation chamber 102 and annealingmay be performed there. Further, when the surface of the cathode isrequired to be cleaned, the substrate is transported to the pretreatmentchamber 103 connected to the transportation chamber 102 and cleaning maybe performed there.

It is also possible to form the poly(ethylenedioxythiophene)/poly(styrene sulfonate) aqueous solution (PEDOT/PSS)serving as a hole injection layer on the entire surface of the anode asneeded. In the manufacturing apparatus of FIG. 11, the film formationchamber 105 for forming the organic compound layer made of a polymer isprovided. When a spin coating method, an ink jet method, or a spraymethod is used for the formation thereof, the substrate is set under theatmospheric pressure such that a surface subjected to film formation isfaced upward. The substrate is inverted as appropriate in the substrateinverting chamber 120 provided between the film formation chamber 105and the transportation chamber 102. Also, after the film formation isperformed using the aqueous solution, it is preferable to transport thesubstrate to the pretreatment chamber 103 where moisture is vaporized byperforming heat treatment in the vacuum.

Next, a substrate 104 c is transported to the transportation chamber 104from the transportation chamber 102 without being exposed to theatmosphere and then, transported to the film formation chamber 106R by atransportation mechanism 104 b to form on the cathode 200 the EL layerfor emitting a red light as appropriate. Here, an example in which it isformed by evaporation is shown. The substrate is set in the filmformation chamber 106R after being inverted in the substrate invertingchamber 120 such that the surface subjected to film formation is faceddownward. Note that, it is preferable to perform vacuum exhausting onthe film formation chamber before the substrate is carried therein.

For example, in the film formation chamber 106R subjected to vacuumexhausting to 5×10⁻³ Torr (0.665 Pa) or less, preferably 10⁻⁴ to 10⁻⁶ Pain degree of vacuum, evaporation is conducted. At the time ofevaporation, the organic compounds are vaporized in advance byresistance heating and are scattered toward the substrate when a shutter(not shown) is opened at this time. The vaporized organic compounds arescattered upward and evaporated onto the substrate through the opening(not shown) provided on the metal mask (not shown). Note that, upon theevaporation, a substrate temperature (T₁) is set to 50 to 200° C.,preferably 65 to 150° C., using a means for heating the substrate.

When the three types of EL layers are formed in order to attain a fullcolor display, after being formed in the film formation chamber 106R,they may be formed through film formation in the film formation chambers106G and 106B in order.

After the desired EL layer 201 is formed on the cathode (or the anode)200, the substrate is transported to the transportation chamber 107 fromthe transportation chamber 104 without being exposed to the air and issubsequently transported to the transportation chamber 108 from thetransportation chamber 107 also without being exposed to the air.

Next, the substrate is transported to the film formation chamber 109using a transportation mechanism placed in the transportation chamber108. The anode 202 made of a transparent conductive film (ITO etc.) isformed on the EL layer 201 as appropriate. In the case where the cathodeis formed, a thin metal layer serving as a cathode is formed in the filmformation chamber 110, the substrate is then transported to the filmformation chamber 109 to form a transparent conductive film, and alaminate consisting of the thin metal layer (cathode) and thetransparent conductive film is appropriately formed. In this case, thefilm formation chamber 110 corresponds to an evaporation apparatusincluding Mg, Ag, or Al used as the cathode as an evaporation source andthe film formation chamber 109 corresponds to a sputtering apparatusincluding at least a target made of a transparent conductive materialused as the anode.

Next, the substrate is transported to the film formation chamber 112using a transportation mechanism placed in the transportation chamber108, in which the film 203 containing hydrogen is formed within a rangeof temperature to which the organic compound layer can be resistant. Inthis case, the film formation chamber 112 is provided with a plasma CVDapparatus and as a reaction gas used for the film formation, a hydrogengas and a hydrocarbon-based gas (e.g., CH₄, C₂H₂, C₆H₆, or the like) areused to thereby form the DLC film containing hydrogen. Note that, thereis not imposed a particular limitation thereon as long as a means forgenerating a hydrogen radical is provided therefor. At the time of thefilm formation of the DLC film containing hydrogen, the defects in theorganic compound layer is terminated with hydrogen turned into a plasma.

Subsequently, the substrate is transported to the film formation chamber113 from the transportation chamber 108 without being exposed to the airto form the protective film 204 on the film 203 containing hydrogen.Here, the sputtering apparatus is employed in which the target ofsilicon or silicon nitride is included in the film formation chamber113. An atmosphere of the film formation chamber is set to a nitrogenatmosphere or an atmosphere containing nitrogen and argon, so that thesilicon nitride film can be formed.

Through the above steps, the laminate structure shown in FIG. 4A, i.e.,the light emitting element covered with the protective film and the filmcontaining hydrogen is formed on the substrate.

Next, the substrate having formed the light emitting element thereon istransported to the transportation chamber 111 from the transportationchamber 108 without being exposed to the air and further, is transportedto the transportation chamber 114 from the transportation chamber 111.

Following this, the substrate having formed the light emitting elementthereon is transported to the sealing chamber 116 from thetransportation chamber 114. Here, it is preferable to prepare a sealingsubstrate provided with a sealing member in the sealing chamber 116.

The sealing substrate is set in the sealing substrate loading chambers117 a and 117 b from the outside. Here, in order to eliminate theimpurity such as moisture, it is preferable to perform annealing inadvance in the vacuum, for example, in the sealing substrate loadingchambers 117 a and 117 b. When the sealing member is formed on thesealing substrate, after the transportation chamber 108 is set to anatmospheric pressure, the sealing substrate is transported to thedispenser chamber 115 from the sealing substrate loading chamber, thesealing member is formed for bonding it to the substrate on which thelight emitting element is formed, and the sealing substrate havingformed the sealing member thereon is transported to the sealing chamber116.

Next, for degassing the substrate on which the light emitting element isformed, annealing is performed in the vacuum or in the inert gasatmosphere. Then, the sealing substrate having formed the sealing memberthereon and the substrate having formed the light emitting elementthereon are bonded to each other. Also, a sealed space is filled withhydrogen or inert gas. Note that, in this case, an example is shown inwhich the sealing member is formed on the sealing substrate, but thepresent invention is not particularly limited to this and the sealingmember may be formed on the substrate having formed the light emittingelement thereon.

Next, a pair of substrates bonded to each other are transported from thetransportation chamber 114 to the ultraviolet irradiating chamber 118,where the substrates are irradiated with a ultraviolet light to cure thesealing member. Note that, in this example, ultraviolet curable resin isused for the sealing member, but any sealing member can be used with noparticular limitation as long as it is an adhesive.

Subsequently, the substrates are transported from the transportationchamber 114 to the delivery chamber 119 and are taken out.

As described above, the manufacturing apparatus shown in FIG. 11 isused, which makes it possible to prevent the light emitting element frombeing exposed to the outside air until it is completely enclosed in thesealed space. Thus, the light emitting device high in reliability can bemanufactured. Note that, the transportation chambers 102 and 114 takerepeatedly a vacuum state and a state at atmospheric pressure, whereasthe transportation chambers 104 a and 108 are always kept vacuum.

Note that, a film formation apparatus of an in-line system can beemployed.

Further, FIG. 12 shows a manufacturing apparatus partially differentfrom that of FIG. 11.

FIG. 11 shows an example in which the film formation chamber for formingthe film using the spin coating method, ink jet method, or spray methodis singly formed, whereas in an example of the manufacturing apparatusof FIG. 12, three film formation chambers for forming the film using thespin coating method, ink jet method, or spray method are formed. Forexample, when three types of EL layers are formed for achieving a fullcolor display by the spin coating method, ink jet method, or spraymethod, after the film formation in the film formation chamber 121 a,they may be formed sequentially in the respective film formationchambers 121 b and 121 c.

Note that, this embodiment can be freely with one of Embodiment Mode 1to Embodiment Mode 5 and Embodiment 1.

Embodiment 3

The EL modules (active matrix EL module, passive EL module) can becompleted by implementing the present invention. Namely, all of theelectronic equipments are completed by implementing the presentinvention.

Following can be given as such electronic equipments: video cameras;digital cameras; head mounted displays (goggle type displays); carnavigation systems; car stereos; personal computers; portableinformation terminals (mobile computers, cell phones or electronic booksetc.) etc. Examples of these are shown in FIG. 13 and FIG. 14.

FIG. 13A is a personal computer which comprises: a main body 2001; animage input section 2002; a display section 2003; and a keyboard 2004etc.

FIG. 13B is a video camera which comprises: a main body 2101; a displaysection 2102; a voice input section 2103; operation switches 2104; abattery 2105 and an image receiving section 2106 etc.

FIG. 13C is a mobile computer which comprises: a main body 2201; acamera section 2202; an image receiving section 2203; operation switches2204 and a display section 2205 etc.

FIG. 13D is a goggle type display which comprises: a main body 2301; adisplay section 2302; and an arm section 2303 etc.

FIG. 13E is a player using a recording medium in which a program isrecorded (hereinafter referred to as a recording medium) whichcomprises: a main body 2401; a display section 2402; a speaker section2403; a recording medium 2404; and operation switches 2405 etc. Thisapparatus uses DVD (Digital Versatile Disc), CD, etc. for the recordingmedium, and can perform music appreciation, film appreciation, games anduse for Internet.

FIG. 13F is a digital camera which comprises: a main body 2501; adisplay section 2502; a view finder 2503; operation switches 2504; andan image receiving section (not shown in the figure) etc.

FIG. 14A is a portable telephone which comprises: a main body 2901; avoice output section 2902; a voice input section 2903; a display section2904; operation switches 2905; an antenna 2906; and an image inputsection (CCD, image sensor, etc.) 2907 etc.

FIG. 14B is a portable book (electronic book) which comprises: a mainbody 3001; display sections 3002 and 3003; a recording medium 3004;operation switches 3005 and an antenna 3006 etc.

FIG. 14C is a display which comprises: a main body 3101; a supportingsection 3102; and a display section 3103 etc.

In addition, the display shown in FIG. 14C has small and medium-sized orlarge-sized screen, for example a size of 5 to 20 inches. Further, tomanufacture the display part with such sizes, it is preferable tomass-produce by gang printing by using a substrate with one meter on aside.

As described above, the applicable range of the present invention isextremely large, and the invention can be applied to electronicequipments of various areas. Note that the electronic devices of thisembodiment can be achieved by utilizing any combination of constitutionsin Embodiment Modes 1 to 5, Embodiment 1 or 2.

According to the present invention, the defect in the organic compoundlayer can be terminated with hydrogen, whereby the light emitting devicecan be increased in its reliability.

Also, according to the present invention, it is possible to dispensewith the circular polarization film extremely expensive, whereby themanufacturing cost can be reduced.

Also, according to the present invention, it is possible to realize highdefinition, high opening ratio, and high reliability in the flat paneldisplay capable of full color display using light emission colors ofred, green, and blue.

1. A light emitting device comprising: a pixel portion having aplurality of light emitting elements, each including a first electrodeelectrically connected to a thin film transistor, an organic compoundlayer formed on the first electrode, and a second electrode formed onthe organic compound layer; a driver circuit; and a terminal portion,wherein an end portion of the first electrode is covered with aninsulator, a third electrode comprising a conductive material is formedon the insulator, the organic compound layer is formed on the insulatorand the first electrode, and the second electrode is formed on theorganic compound layer and in contact with the third electrode, andwherein a portion where a wiring comprising a same material as the thirdelectrode or the second electrode is connected with a wiring extendedfrom a terminal is formed between the terminal portion and the pixelportion.
 2. A light emitting device according to claim 1, wherein thethird electrode has a pattern shape identical to that of the insulator.3. A light emitting device according to claim 1, wherein the thirdelectrode has a pattern shape different from that of the insulator.
 4. Alight emitting device comprising: a pixel portion having a plurality oflight emitting elements, each including a first electrode electricallyconnected to a thin film transistor, an organic compound layer formed onthe first electrode, and a second electrode formed on the organiccompound layer; a driver circuit; and a terminal portion, wherein an endportion of the first electrode is covered with an insulator, the organiccompound layer is formed on the first electrode and a part of theinsulator, the second electrode is formed on the organic compound layer,and a third electrode is formed on a region of the second electrodewhich is not overlapped with the first electrode, and wherein a portionwhere a wiring comprising a same material as the third electrode or thesecond electrode is connected with a wiring extended from a terminal isformed between the terminal portion and the pixel portion.
 5. A lightemitting device according to any one of claims 1 and 4, wherein thesecond electrode is a cathode or an anode of the light emitting element.6. A light emitting device according to any one of claims 1 and 4,wherein the third electrode comprises at least one selected from thegroup consisting of poly-Si doped with an impurity element imparting aconductivity type, W, WSi_(x), Al, Ti, Mo, Cu, Ta, Cr, and Mo, a filmmainly containing an alloy material or a compound material mainlycontaining thereof, or a laminate film thereof.
 7. A light emittingdevice according to any one of claims 1 and 4, wherein the firstelectrode is a cathode or an anode of the light emitting element.
 8. Alight emitting device according to any one of claims 1 and 4, whereinthe insulator is a barrier comprising an organic resin covered with aninorganic insulating film.
 9. A light emitting device according to anyone of claims 1 and 4, wherein the insulator is an inorganic insulatingfilm.
 10. A light emitting device according to any one of claims 1 and4, wherein the third electrode comprises a laminate having a nitridelayer or a fluoride layer as an uppermost layer.
 11. A light emittingdevice according to any one of claims 1 and 4, wherein the inorganicinsulating film comprises silicon nitride.
 12. A light emitting deviceaccording to any one of claims 1 and 4, wherein the light emittingdevice has a color filter corresponding to each of pixels composed ofthe light emitting element.
 13. A light emitting device comprising: alight emitting element over a substrate having an insulating surface,the light emitting element including an anode, a cathode, and an organiccompound layer interposed between the anode and the cathode, wherein thelight emitting element is covered with a film containing hydrogen.
 14. Alight emitting device comprising: a light emitting element over asubstrate having an insulating surface, the light emitting elementincluding an anode, a cathode, and an organic compound layer interposedbetween the anode and the cathode, wherein the light emitting element iscovered with a film containing hydrogen, and wherein the film containinghydrogen is covered with a protective film comprising an inorganicinsulating film.
 15. A light emitting device comprising: a lightemitting element over a substrate having an insulating surface, thelight emitting element including an anode, a cathode, and an organiccompound layer interposed between the anode and the cathode, wherein thelight emitting element is sealed with a substrate having alight-transmissive property and a sealing member, and wherein a sealedspace contains hydrogen.
 16. A light emitting device according to claim15, wherein the light emitting element is covered with the filmcontaining hydrogen.
 17. A light emitting device according to any one ofclaims 13 to 15, wherein the film containing hydrogen comprises carbonor a silicon nitride film.
 18. A light emitting device according to anyone of claims 1, 4, and 13 to 15, wherein the light emitting device isincorporated in at least one selected from the group consisting of apersonal computer, a video camera, a mobile computer, a goggle typedisplay, a player using a recording medium, a digital camera, a portabletelephone, an electronic book, and a car navigation system.
 19. A methodof manufacturing a light emitting device comprising: forming a thin filmtransistor on an insulating surface; forming a cathode electricallyconnected to the thin film transistor; forming an organic compound layeron the cathode; forming an anode on the organic compound layer; andforming a film containing hydrogen on the anode.
 20. A method ofmanufacturing a light emitting device comprising: forming a thin filmtransistor on an insulating surface; forming an anode electricallyconnected to the thin film transistor; forming an organic compound layeron the anode; forming a cathode on the organic compound layer; andforming a film containing hydrogen on the cathode.
 21. A method ofmanufacturing a light emitting device according to any one of claims 19and 20, wherein the film containing hydrogen is formed by a plasma CVDmethod or a sputtering method.
 22. A method of manufacturing a lightemitting device according to any one of claims 19 and 20, wherein thefilm containing hydrogen comprises carbon or a silicon nitride film. 23.A method of manufacturing a light emitting device according to any oneof claims 19 and 20, wherein a step of forming the organic compoundlayer is performed by an evaporation method, a coating method, an ionplating method, or an ink jet method.
 24. A method of manufacturing alight emitting device according to any one of claims 19 and 20, whereina protective film comprising an inorganic insulating film is formed onthe film containing hydrogen.
 25. A method of manufacturing a lightemitting device according to any one of claims 19 and 20, wherein adefect in the organic compound layer is terminated with hydrogen whenthe film containing hydrogen is formed.
 26. A method of manufacturing alight emitting device according to any one of claims 19 and 20, whereinthe light emitting device is incorporated in at least one selected fromthe group consisting of a personal computer, a video camera, a mobilecomputer, a goggle type display, a player using a recording medium, adigital camera, a portable telephone, an electronic book, and a carnavigation system.